HP 9000 Superdome SX2000 Generic Site Preparation Guide - Edition 6 - Page 9

NOTE: Set cooling for the maximum-rated power output of the room, and develop a growth plan for the cooling infrastructure. Grounding Systems WARNING! Follow electrical code when connecting equipment AC power ground wire to the AC distribution point. Failure to properly ground the equipment or the floor can lead to shock hazard. HP computer hardware has been tested only on systems where protective earth is integral to the electrical distribution system. This grounding is crucial for personnel safety and for maximum equipment availability and use. Observe the following precautions: • Neutral and ground wires have specific uses. Do not interchange them. • Do not use conduit grounds in place of a separate grounding conductor to each receptacle. • Size ground wires to be equal to the power source wires. • Do not daisy chain phase, neutral, and ground wires. • If the system is on raised flooring, use a 2-foot by 2-foot (61-cm by 61-cm) grounding grid. Comprehensive Discussion IMPORTANT: Electrical practices and suggestions in this guide are based on North American practices. For regions and areas outside North America, local electrical codes take precedence over North American electrical codes. For example, the recommendation that the Protective Earth (PE) conductor be green with a yellow stripe, is a European Union (EU) directive. North American local electrical inspectors will accept a ground wire if the color is green with a yellow stripe. Local authority has jurisdiction (LAHJ) and should make the final decision regarding adherence to region-specific or area-specific electrical codes and guidelines. The proper design and installation of a product power distribution system requires specialized skills. Those responsible for this task must have a thorough knowledge of appropriate electrical codes and the limitations of the power systems for computer and data processing equipment. In general, a power distribution system should exceed the requirements of most electrical codes. A good design, when coupled with proper installation practices, produces the most trouble-free operation. A detailed discussion of power distribution system design and installation is beyond the scope of this guide. However, electrical factors relating to power distribution system design and installation must be considered during the site preparation process. The following electrical factors are discussed in this section: • Computer room safety • Power consumption • Electrical load requirements (circuit breaker sizing) • Power quality • Distribution hardware • System installation guidelines Electrical Factors 9